@negative12dollarbill @futurebird
This is one of my favourite linguistic quirks and relevant to the other thread about hyphenation from yesterday. In English, you hyphenate based on root words, so helico-pter is the correct hyphenation, but in American you hyphenate based on syllables and so heli-copter is correct. I prefer the American rules because they give a pronunciation hint, whereas the English rules are just there to let you say 'Oh, you don't speak Latin / Greek / French / Celtic / Proto-Germanic / ... ? Peasant!'.
This makes quad copters a silly word, they really should be quad pters or similar.
Mind you, that's nowhere near as meaningless as 'quad bike', a noun phrase that just means four two. It's lost the cycle (bi-cycle: two wheels) but kept the root word that describes the one bit that it's changed. And I will insist on referring to them as quadracycles.